Allegro Leadership

Allegro Leadership


Brett Vandenberg, CMPE

Chief Executive Officer

Born and raised in Seattle, Brett Vandenberg is the Chief Executive Officer of Allegro Pediatrics. Brett has an almost 20-year career in Healthcare Administration, holding a certification as a Medical Practice Executive from the Medical Group Management Association (MGMA). He was twice the President of the Washington State Chapter of MGMA and still serves on their Board. Brett also serves as a liaison to the Washington State Medical Association Board of Directors. His personal time is spent enjoying the outdoors, especially golf and other sports. He is a lifelong “Husky” after having attended the University of Washington. Brett also volunteers as a finance committee member with the non-profit organization Kindering that serves children from birth to 3 years old on the Eastside. He and his wife live in Kirkland with their two kids.   


Amy Carter, MD, FAAP

Chief Medical Officer 

Dr. Amy Carter graduated magna cum laude from Harvard University. While living in Boston, she was part of the founding group of Project Health students working at Boston Medical Center to advocate for social determinants of health. Dr. Carter then followed her husband to Palo Alto to work in Kaiser Permanente California’s strategic planning department. She eventually returned home to the University of Nevada for medical school, where she graduated first in her class. Dr. Carter completed her pediatric fellowship at the University of Washington/Seattle Children’s and joined Allegro Pediatrics in 2007. In addition to focusing on her busy pediatric practice, partnering with families on their journeys toward health, she has been a member of the Allegro Board of Directors since 2013, and has participated in a regional outpatient pediatric quality guidelines committee. Dr. Carter is now Allegro’s Chief Medical Officer, with the goal of promoting clinical quality and developing an integrated behavioral health care strategy. Dr. Carter is married with two children. She enjoys bicycling, traveling, reading, exploring restaurants, and scorekeeping for her sons’ baseball games.


Holly Ginsberg, MD, FAAP

Chief Personnel Officer

Dr. Holly Ginsberg has been a primary care pediatrician since 2001 and joined our practice in 2007. She assumed the role of Chief Personnel Officer in January 2021. As the CPO for Allegro Pediatrics, Dr. Ginsberg is responsible for recruiting and staffing our physicians, nurse practitioners, and physician assistants. She promotes and helps facilitate not only their ability to provide excellent medical care, but also to obtain professional development and maintain the delicate balance between work and life. She attended Stanford University for her undergraduate education, then the Perelman School of Medicine at the University of Pennsylvania. She completed her pediatric residency at the Lucile Packard/Stanford Children’s Hospital. Dr. Ginsberg has a variety of pediatric interests, including infant development and adolescent wellness. Mostly, she enjoys showing parents what amazing capabilities their babies and children have! Dr. Ginsberg and her husband have two busy teenage daughters and two lazy dogs. She enjoys art, music, literature, and learning different languages and cultures. She also relishes every minute she spends driving her daughters to soccer and ballet!


Steve Schiebel, MD, FAAP

Chief Medical Information Officer

Dr. Steve Schiebel joined Allegro Pediatrics in June 2000. Dr. Schiebel attended medical school at Baylor College of Medicine, but wasn’t initially sure what his focus should be in medicine. He really enjoyed working with children during his pediatric rotations, and decided to become a pediatrician. In addition to his passion for practicing medicine, Dr. Schiebel has a strong interest in technology and business. This led to his instrumental role in the implementation, design, and management of the first electronic health record system at Allegro Pediatrics. When it came time to transition to a new EHR, Dr. Schiebel was asked to lead the project and accepted the position of Chief Medical Information Officer. Dr. Schiebel is married, with two young girls. Two cats and a very active dog complete the family. He enjoys attending Seattle Mariners games with his family, skiing, hiking, reading, and being his family’s I.T. guru.


Glenn Lux, MD, MBA

Former President & Chief Executive Officer, Retired

Dr. Glenn Lux joined our practice in 1977. He moved into the role of president in 1987, and the role of Chief Executive Officer in 2000, but continued to see patients in addition to his administrative duties until 2009. He retired from his administrative positions in November 2019. Dr. Lux attended Amherst College for his undergraduate studies, University of Rochester for medical school, and completed his MBA at Seattle University. He is board-certified in pediatrics. Before joining Allegro Pediatrics, Dr. Lux was a medical officer for the United States Navy at the Sand Point Naval Medical Clinic. He is a President Emeritus of Kindering Center and still serves as a member of its Board of Directors. Dr. Lux is also a member of the Washington State Medical Association Judicial Council and a clinical associate professor emeritus at the University of Washington. Dr. Lux is on the affiliate faculty of the Albers School of Business and Economics at Seattle University, where he is on the faculty of the course “Leading with Emotional Intelligence.” He is also the author of EQ Primer-3rd edition. Dr. Lux has two daughters and a grandson, and enjoys spending time with his family. He also enjoys choral singing, hiking, traveling, and the study of Italian language. 


Katie Brierley

Director of Clinical Operations

Katie Brierley oversees the operations of all nine Allegro Pediatrics clinic sites and the medical records department. She joined our practice in 2010 after attending the University of Washington where she was a member of the UW crew team. Prior to taking on her current responsibilities, Katie worked in an administrative role as project manager and most recently as manager of the IT department.  She had direct responsibility for managing Allegro’s IT team, in addition to overseeing technical projects and training. Katie lives in Seattle and enjoys hiking, trying new restaurants, and traveling.


Ingrid Joseph

Director of Human Resources

Ingrid Elwin Joseph joined our team in July 2019. She oversees staff development, payroll, benefits, hiring, and employment compliance for Allegro Pediatrics. Ingrid has a strong science and technology-focused background in her more than twenty years as an HR professional. Her diverse experience includes positions at Nordstrom, Microsoft,, and a variety of engineering, software, medical device, and biotech companies. Before coming to Allegro Pediatrics, Ingrid was the Director of Human Resources at Infectious Disease Research Institute. She is a SHRM/HRCI certified Human Resources Professional. Ingrid and her husband enjoy traveling the world.


Kevin Nelson

Director of Finance

Kevin Nelson has been with Allegro since 2008. Prior to his current role, he served mainly as the company’s Comptroller. Kevin graduated from the University of Washington Business school and has a diverse background of business experience. From working in the marketing department for the Seattle Supersonics to self-employed videography work, Kevin enjoys using his array of interests to blend his creative and analytic mindset to better understand the nuances that help a company thrive financially. He enjoys sports (Hawks season ticket holder, Go Hawks!), being outdoors in the sun, music, and traveling the world. He currently lives on the Eastside with his wife and two dogs.


Andrea Petre, MBA, FACMPE

Director of Internal Operations  

Andrea Petre oversees facilities, environmental services, materials management, and company events for Allegro Pediatrics. She joined our practice in 1998, and enjoys working closely with the doctors and staff to impact the overall patient experience. Andrea has an MBA, her Six Sigma Yellow Belt certification, and is a Certified Medical Practice Executive (CMPE) from the Medical Group Management Association (MGMA). She is also a Fellow in the American College of Medical Practices Executives (FACMPE), a board member for the Washington State chapter of the MGMA, and a volunteer for the national MGMA organization.  Andrea is married with three children that have been patients at Allegro. She enjoys spending time with her family and paddle boarding.


Vicki Barag, MSN, RN

Director of Clinical Services

Vicki Barag, MSN, RN oversees the clinical services of all Allegro Pediatrics clinic sites as well as the referrals department, afterhours nurse program and training department. She joined our practice in 2014 after moving across the country with her now husband from New Jersey. Prior to taking on this new role she served as a nurse, back-office lead, vaccine coordinator and later became the Clinical Services Coordinator. Vicki is responsible for ensuring that Allegro Pediatrics patients experience high quality and patient-centered care. Vicki serves as the liaison with the King County Vaccines for Children (VFC) program as well as other community partners and agencies to ensure compliance. She is a member of the American Academy of Ambulatory Care Nursing. She received her Master of Science in Nursing degree from Grand Canyon University in 2018. She currently lives in Shoreline with her husband and dog, Zipper. Vicki enjoys trying new restaurants, road trips, soaking up the sun, and spending time with her family and friends.